Sheet transfer roller for use in multicolor rotary printing presses

ABSTRACT

A sheet transfer roller for use in multicolor printing presses is formed by a number of sets of arcuate elements arranged concentrically with the roller axis and slidably mounted on respective guides carried by the roller and extending parallel to the roller axis. The arcuate element can be clamped to the guides at the desired positions by clamping screws. It can be arranged that sheet supporting members carried by the arcuate elements engage a sheet to be transferred at selected relatively printfree regions.

United States Patent Papa et al.

[ Feb. 22, 1972 [54] SHEET TRANSFER ROLLER FOR USE IN MULTICOLOR ROTARY PRINTING PRESSES [72] inventors: Paolo Papa; Federico Capetti, both of Turin, Italy [73] Assignee: Societa Nebiolo S.p.A., Turin, Italy [22] Filed: Dec. 1, 1969 [21] Appl. No.: 881,046

[30] Foreign Application Priority Data Nov, 0. I96) ltniy ..50258 [52] US. Cl. ..101/420, 271/51 [51] Int. Cl ..B4ll4l/06 [58] Field ofSearch ..101/416, 420,4l5.7; 29/124;

[56] References Cited UNITED STATES PATENTS Pasquinelli .....1( 1 /420 x Woodward 101/420 3,261,288 7/1966 Dickerson ....10l/420 3,334,892 2/1967 Jonecek et al. ..271/51 3,126,826 3/1964 Fischer ..271/5i X Primary Examiner-William B. Penn Assistant ExaminerE. M. Coven Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak ABSTRACT A sheet transfer roller for use in multicolor printing presses is formed by a number of sets of arcuate elements arranged concentrically with the roller axis and slidably mounted on respective guides carried by the roller and extending parallel to the roller axis. The arcuate element can be clamped to the guides at the desired positions by clamping screws. it can be arranged that sheet supporting members carried by the armate elements engage a sheet to be transferred at selected relatively print-free regions.

4 Claims, 7 Drawing Figures PATENTEDFEB 22 I972 3. 643 598 SHEET 1 [IF 4 Fig.1

PAIENTEDFEB 2 2 I972 SHEET 4 [IF 4 SHEET TRANSFER ROLLER FOR USE IN MULTICOLOR ROTARY PRINTING PRESSES This invention relates to sheet transfer rollers, particularly for use in multicolor rotary printing presses.

Known arrangements for transferring sheets between two printing elements in multicolor printing presses comprise a certain number of intermediate transfer rollers.

With such arrangements each sheet is withdrawn from the printing cylinder and is transferred by the transfer rollers to the next printing element of the printing press. During transfer the printed face of the sheet may be soiled and its quality impaired either because it comes into direct contact with the peripheral supporting surfaces of the transfer roller or because dry ink previously deposited on said supporting surfaces scratches the fresh print on the sheet.

In order to obviate these drawbacks it has been proposed to arrange concentrically on the shaft for each transfer roller a number of sectors providing the sheet supporting surfaces, means being provided for effecting axial displacement of the sectors.

Further known arrangements consist in providing the transfer rollers with arcuate strips made of metal, plastics, leather or other suitable material, which are displaceable parallel to the roller axis to positions in which they support regions of the sheet which are free from prints.

However, the above known arrangements are unsatisfactory where the sheet to be transferred has substantially no printfree regions extending throughout the length of the sheet.

In any case, placing the sheet supporting surfaces in such manner that they contact the sheets only at blank regions or part-printed regions of the sheets, requires a tedious and lengthy preparation of the transfer roller which is inconsistent with the need for economical operation of the printing press.

Still further known arrangements consist in coating the skirts of the transfer rollers with ink-repellent materials. In actual practice, however, not even the use of such materials will prevent ink from being deposited on the supporting surfaces of the rollers. The latter should therefore be washed frequently if damage to the printed sheets is to be prevented, and this also entails heavy losses of production time in the printing press.

It willbe apparent, therefore, that none of the known arrangements solve satisfactorily either the problem of transferring printed sheets by transfer rollers, or the problem, which follows from the first-mentioned problem, of maintaining within reasonable limits the necessary time for preparing the printing press for printing a given pattern or form.

An object of the present invention is to substantially avoid, or minimize, these drawbacks by providing an improved sheet transfer roller for use particularly in multicolor rotary printing presses.

Accordingly the invention provides a sheet transfer roller, for use in multicolor rotary printing presses, for supporting a sheet during transfer of the latter between successive printing elements of the press, characterized by the improvement which consists in said roller including a plurality of sets of arcuate elements concentric with the roller axis, respective guides extending parallel to the axis of the roller, the arcuate elements associated with each respective set being slidably mounted on said guides, means supporting said guides from the roller, and means on said arcuate elements effective to hold said elements in position along their respective guides.

Each arcuate element is conveniently provided with sheet supporting means arranged adjacent the outer periphery of the element and secured thereto. Preferably the sheet supporting means are movably mounted on the respective arcuate elements so that each sheet supporting means can be disposed at will in either of two different positions, namely an inoperative position and an operative position, a sheet supporting part of the said supporting means being spaced further from the roller axis in the operative position of the supporting means than in the inoperative position thereof.

Each said sheet supporting means preferably comprises a substantially rectangular loop mounted in proximity to the outer periphery of one face of the respective arcuate element and capable of tilting laterally about one of its shorter sides extending substantially tangentially to the closest part of said outer periphery so as to cause the other shorter side, constituting the sheet supporting part, to be positioned at will either radially inwardly or radially outwardly of said outer periphery.

Further characteristic features and advantages of the invention will be understood from the following description, given by way of nonlimiting example, with reference to the accompanying drawings, wherein:

FIG. 1 is an elevational view of a transfer roller according to one embodiment of the invention;

FIGS. 2 and 3 are cross-sectional views on lines IlII and III-III respectively in FIG. 1;

FIG. 4 is a view on an enlarged scale of a constructional detail of the transfer roller shown in FIGS. 1 to 3;

FIG. 5 is a cross-sectional view on line V-V of FIG. 4;

FIG. 6 is a partly cut away perspective view of the transfer roller according to the invention; and

FIG. 7 shows a graduated transparent sheet for use in preparing the said transfer roller for operation.

The transfer roller shown on the drawings comprises a pair of end discs I, 2 secured to a common rotary shaft 3. The shaft 3 is conveniently supported for rotation near its opposite ends in the frame, part only of which is shown in section, of one printing element of a multicolor rotary printing press.

The shaft 3 carries at one end a gear 3a by which it receives rotary drive from the drive transmission (not shown) of the printing press for imparting rotation to the shaft 3.

The shaft 3 supports two elongated guides 4, 5 which extend parallel with the axis of the shaft 3. The guides 4, 5 are in the form of similar beams equally spaced from the axis of the shaft 3. The guides 4, 5 are each maintained in their respective positions parallel with the axis of the shaft 3 by a plurality "of respective semicircular crescent-shaped supports 4b, 5b frictionally secured to each other and thereby frictionally clamped to the shaft 3 by means of bolts and nuts (FIG. 2). Each support 4b, 512 has an integrally formed bearing arm 4a, 5a to which the respective guide 4, 5 is secured.

The guide 4 supports for axial sliding movement a plurality of similar arcuate segments 6 the periphery 6a of each of which is concentric with the axis of the shaft 3. In addition, the guide 5 has slidably mounted thereon segments 7 equal in number to the segments 6 and similar to the latter, having arcuate peripheries 7a. If desired, the number of segments and angular width of each segment 6, 7 slidably mounted on the respective guide 4, 5 could be different. Also, the segments 6, v

7 could, alternatively, be replaced by other arcuate elements such as sectors. The mutual angular position of the guides 4 and 5 should in any case be such that the spacing of the outer peripheries 6a and 7a of the respective segments 6, 7 carried thereby is smallest when the segments are situated substantially in a common plane passing through the axis of the shaft 3.

In order to prevent rotation of the segments 6, 7 about their respective guides 4, 5, the latter are shaped with a keyhole cross section, including outer portions 4c, 56 respectively, of substantially circular cross section and inner portions 4d, 5d, respectively, of substantially rectangular cross section, connecting the portions 40, 5c to the respective bearing arms 4a, 5a.

The segments 6, 7 are mounted on their respective guides 4, 5 through the interposition of respective lateral supports hubs 6b, 7b. Radial tapped holes are bored in the hubs 6b, 7b and receive clamping screws 8 which are easily accessible. By releasing the clamping screws 8 the segments 6, 7 can'be positioned as desired on their respective guides 4, 5 and then secured in position by tightening the clamping screws.

Each segment 6, 7 is provided with a plurality of supporting means for supporting the sheets during their transfer, when the leading edges of the sheets are clamped to the transfer roller by means of a pair of nippers 9, shown diagrammatically, carried by the roller.

The supporting means are each in the form of a metal loop 10 which is substantially rectangular, having one short side 10a (FIG. 4) slightly convex outwardly and its other short side 10b of a quadrangular cross section in its middle portion (FIG. 5) the remainder of the loop 10 being ofcircular cross section. Each loop i is arranged with its axis'of symmetry in a plane containing the axis of the shaft 3. Each loop 10 carried by any one segment 6 or 7 can rotate about its side 10b by virtue of a hinge attachmentcomprising a pair of brackets 11 supporting opposite ends of the side 10b where the latter has a circular cross section. Each pair of brackets 11 is secured by radially outer and inner rivets l2 and 12' to one face of the respective segment 6 or 7.

-The radiallyouter rivet 12 also retains a small leaf spring 13 (FIGS. 4 and the free end of which bears against the middle on the sheets. This is effected by superposing the transparent sheet 18 on a printed standard sheet and determining the coordinates of the blank regions at which the sheets can be engaged by the loops during transfer thereof by the transfer portion of quadrangular cross section of the side 10b of the 7 loop 10.

With this arrangement, and by virtue of the position of the hinge axis of each loop 10 with respect to the outer periphery 6a, 7a of the respective segment 6, 7, each loop 10 can be tilted, simply by applying finger pressure, from a respective inoperative position denoted by P' (in broken outline) in FIG. 5 to an operative position denoted by P in the same figure. The spring 13 ensures that the loop 10 is resiliently retained in both its operative and inoperative positions P, P, and snaps between these positions. In both the positions-P, P the plane of the loop 10 is slightly inclined with respect to the face of the segment 6, 7 to which it is attached. The force exerted by a sheet being transferred on the convex sides 10a of each loop 10 which projects radially outwardly from the periphery 6a, 7a

of each segment 6, 7 tends to maintain the loop 10 in its operative position P.

The guides 4, 5 are provided with similar spaced apart transversely extending graduation lines 14 and the segments 6, 7 have engraved thereon respective sets of angularly spaced apart numerals l5, 16 respectively, coinciding with the positions of the respective loops 10. The numerals in the set 16 are the continuation of the numerals in set 15, both sets of nu merals l5, 16 being engraved in the segment faces opposite the faces carrying the hinge brackets 11 for the loops 10.

The spacing of the graduation lines 14 on the guide 4, 5 correspond with the spacing of longitudinal rulings 19 marked on a transparent sheet 18 (FIG. 7).

The said transparent sheet 18 further carries horizontal rulings 21, each of which is distinguished by one of the numerals in the sets 15 or 16 engraved on the lateral faces of the segments 6 and 7.

The sheet 18 assists in initially setting up the transfer roller with the segments 6, 7 positioned along their respective guides 4, 5 and in determining the loops 10 which should be moved to their operative positions when printing a given fonn or pattern roller. By means of these coordinates the segments 6, 7 can be positioned easily and accurately along their respective guides 4, 5 and the selected loops [0 can be quickly moved to their operative positions. 1 p

It will be understood that, within the principle of theinvention, constructional details of practical embodiments-can be widely varied from those of the exampledeseribed and shown without departing from the scope of the invention as defined by the appended claims.

What is claimed is: i

1. For use in multicolor rotary printing presses a sheet transfer roller for supporting a sheet during transfer of said sheet between successive printing elements of the press comprising a plurality of sets of arcuate elements concentric with the roller axis, guide means for each of said sets of-arcuate elements extending parallel to the axis of the roller with the arcuate elements assocrated with each set being slrdably mounted on a respective guide means, means supporting said guide means on the roller, means on said arcuate elements for holding said elements in position on their respective guide means, sheet supporting-means, means for pivotally securing a plurality-of said-sheet supporting means to one side of each of said arcuate elements along a curved line concentric with the roller axis and spaced inwardly from the outer periphery of said arcuate elements for selective movement between an inoperative position and an operative position, each of said sheet supporting means being comprised of a substantially rectangular loop having two longer sides and two shorter sides, one of said shorter sides being pivotally mounted on an arcuate element and the other of said shorter sides defining a sheet supporting part which extends beyond the periphery of said arcuate ele' ment in the operative position of said sheet supporting means and which is disposed radially inwardly of the outer periphery of said arcuate element in the inoperative position.

' 2. Roller as claimed in claim 1, wherein the sheet supporting shorter side of each sheet supporting loop is shaped with a slight outwardly convex curvature.

3. Roller as claimed in claim I, wherein the shorter side about which each loop is pivoted has a region of quadrangular cross-sectional shape and further comprising a plurality of leaf springs secured to the respective arcuate elements with one end of each leaf spring bearing upon said quadrangular section a region of each loop, whereby each loop snaps from its init is pivoted.

operative into its operative position and vice-versa.

4. Roller as claimed in claim 3, wherein each loop, at least when in its operative position, is inclined in the direction of the side of the arcuate element remote from the side to which UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 643, 598 Dated February 22, 1972 Inventor(s) Paolo PAPA and Federico CAPETTI It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown belowf.

In the Heading:

The Claim of Priority should read as follows;

--Foreign Application Priority Data January 23; 1969 Italy. 50258-A/69-- Signed and sealed this 3rd day of October 1972.

(SEAL) Attest:

EDWARD M.FLETCIIER,JR. Q ROBERT GOI'TSCHALK Attesting Officer Commissioner of Patents FORM PO-105O (10-69) USCOMM-DC 60876-P69 u.s. GOVERNMENT PRINTING OFFICE Isis O-366-38l 

1. For use in multicolor rotary printing presses a sheet transfer roller for supporting a sheet during transfer of said sheet between successive printing elements of the press comprising a plurality of sets of arcuate elements concentric with the roller axis, guide means for each of said sets of arcuate elements extending parallel to the axis of the roller with the arcuate elements associated with each set being slidably mounted on a respective guide means, means supporting said guide means on the roller, means on said arcuate elements for holding said elements in position on their respective guide means, sheet supporting means, means for pivotally securing a plurality of said sheet supporting means to one side of each of said arcuate elements along a curved line concentric with the roller axis and spaced inwardly from the outer periphery of said arcuate elements for selective movement between an inoperative position and an operative position, each of said sheet supporting means being comprised of a substantially rectangular loop having two longer sides and two shorter sides, one of said shorter sides being pivotally mounted on an arcuate element and the other of said shorter sides defining a sheet supporting part which extends beyond the periphery of said arcuate element in the operative position of said sheet supporting means and which is disposed radially inwardly of the outer periphery of said arcuate element in the inoperative position.
 2. Roller as claimed in claim 1, wherein the sheet supporting shorter side of each sheet supporting loop is shaped with a slight outwardly convex curvature.
 3. Roller as claimed in claim 1, wherein the shorter side about which each loop is pivoted has a region of quadrangular cross-sectional shape and further comprising a plurality of leaf springs secured to the respective arcuate elements with one end of each leaf spring bearing upon said quadrangular section region of each loop, whereby each loop snaps from its inoperative into its operative position and vice-versa.
 4. Roller as claimed in claim 3, wherein each loop, at least when in its operative position, is inclined in the direction of the side of the arcuate element remote from the side to which it is pivoted. 